The invention relates to an articulated joint, in particular a door hinge, having a device for fastening a first movement element which is coupled movably to a second movement element,
having a fastening unit
which has at least one first and one second braking element, the first braking element (for example, outer discs) being connected to the first movement element and the second braking element (for example, inner discs) being connected to the second movement element,
the braking elements being able, by the action of a force generated by a force application element, to be engaged with one another in such a manner that they are fastened to one another, and via the connection of the braking elements to the movement elements, in this case the movement elements are also fastened to one another,
and having a mechanical switching unit.
At present fastening devices are known which comprise
a latching unit,
which is connected in a rotationally fixed manner to a first movement element, and
is in engagement with a latching projection mounted on a second movement element.
This type of fastening describes a mechanical door-holding system for motor vehicles which is customary in practice. These door-holding systems have defined latching points which are specified by the latching unit used. These latching points define the door-opening angles in which the position of the door, relative to the frame, is secured against slamming shut or opening. Fastening the door at any desired opening angle cannot be achieved using the known mechanical door-holding systems. In everyday life this has the consequence that in the event of an obstacle, for example another vehicle, a wall or the like, being situated in the predetermined latching position of the door, the door has to be fastened in the next smaller latching position, as a result of which, however, getting in or out is made substantially more difficult. Alternatively, there is only the option of holding the door open. However, this generally results in there being collisions with the object which result in unwanted damage.
A further disadvantage of the known door-holding systems resides in the fact that the doors are accelerated by their own latching system in the direction of the nearest latching. This has the result that the door, after being released outside the latching points, is accelerated in the direction of a possible obstacle and the door collides with the obstacle. Depending on the magnitude of the impact speed, these collisions cause damage, in particular damage to the paint, which has to be repaired at high cost.
Known catches which make it possible to lock the door in any desired position, require an electric or hydraulic auxiliary device in order to actuate braking elements which serve to fix the door. These systems are very susceptible to faults, have a high inherent weight and cause high manufacturing costs.
From document DE 41 03 198 a device is known which corresponds to the type of articulated joint the most important features of which are described in the beginning above. Said document discloses a door of a motor vehicle provided with a brake which holds the door in the open position. The brake consists of an arm attached to the hinge pin. The arm is provided with two radially adjustable blocks which have recesses to receive the rounded heads of brake shoes. Each brake shoe can swing around an axis, which is parallel to the hinge axis, and the brake shoe is in permanent contact with the inside surface of a bushing. Thus in case of a sufficient pressure between the brake shoe and the inside surface of the bushing to secure the desired opening position of the door it is not possible to freely pivot the door with respect to a frame because the pressure can not be reduced. Vice versa a reduction of the pressure which makes it possible to pivot the door with respect to the frame would have the undesired effect that the opening positions of the door are not sufficiently secured. Further a sufficient high pressure on the brake shoe, i.e. sufficiently high for holding the door, would necessarily cause a damage of the inside surface of the bushing.
It is therefore the object of the present invention to provide, with the abovementioned disadvantages being avoided, a fastening device of the type mentioned at the beginning which makes it possible for the movement elements to be locked in any desired relative position with respect to one another in a mechanical manner.
According to the invention, this object is achieved by use being made of the mechanical switching unit,
which can take up a coupling state and at least one separating state,
the switching unit switching over from the coupling state into the separating state when the movement elements move relative to one another,
in the coupling state the switching unit releasing the action of a force on the braking elements, so that said braking elements enter into engagement with one another,
and the switching unit comprising
a first and second actuating element, the first actuating element (for example, upper lifting washer) being connected to the first movement element and the second actuating element (for example, lower lifting washer) being connected to the second movement element in such a manner that the movement of the movement elements causes a rotational movement of the actuating elements, which are mounted on one another in such a manner that when there is a mutual change in their position they execute a switching movement taking place in a direction which is parallel to the axis of rotation and the actuating elements change their distance apart which causes the switching unit to switch over from the coupling state into the seperating state in which the action of the force on the braking elements is blocked, so that said braking elements become detached from one another and
at least one coupling element like a rolling or tilting body (for example balls) which converts the relative movement of the movement elements into a switching movement of the actuating elements, the coupling element returning automatically into its starting position releasing the action of the force on the braking elements, so that said braking elements reenter into engagement with one another.
Movement elements may be all of the parts which can be moved relative to one another and which are connected to one another. Movement elements can, in particular, be motor-vehicle doors which are connected to the vehicle body at a frame.
Locking of the movement elements with respect to one another, for example the fastening of a motor-vehicle door with respect to the body, takes place with the aid of the braking elements. These braking elements are connected to the associated movement elements in such a manner that the fastening of the braking elements leads to the fastening of the associated movement element.
In order to lock the movement elements in their relative position, the braking elements can be brought into mutual engagement. The type of connection between the particular braking elements can be selected in accordance with the particular application. Frictional or interlocking connections, inter alia, can thus be used.
In order to secure the connection of the engaged braking elements, said braking elements are acted upon with a force. The size of the force determines, inter alia, the counter-force which is necessary in order to detach the connection between the braking elements.
The mechanical switching unit, which is actuated by a movement of the movement elements relative to one another, is the central point of the invention. The movement of the movement elements causes the mechanical switching unit to be switched over from the coupling state, in which a force acts on the braking elements so that said braking elements enter into engagement with one another, into the separating state, as a result of which the action of the force on the braking elements is interrupted and the latter become detached from one another. Referring to the example of a motor-vehicle door, this means that by means of a door movement the mechanical switching unit switches from the coupling state into the separating state, by the door being freely pivotable with respect to the frame, until the pivoting movement of the door is at an end and the switching unit passes back into the coupling state in which it releases the force in order to fasten the braking elements.
Owing to this arrangement the automatic fastening and separating of the movement elementsxe2x80x94i.e., for example, of the door with respect to the framexe2x80x94is possible in every desired relative position. In this arrangement, the braking elements do not have to be brought into engagement or the braking elements which are in engagement do not have to be detached by a separate, external switching procedure if it is intended to fasten the movement elements or to move them relative to one another.
A coupling element is a body which can be arranged between the actuating elements and with which it is in point or linear or planar contact. A relative movement of the actuating elements causes the coupling elements to change their relative position with respect to the actuating elements, the distance between the actuating elements changing. Use can be made, among other things, of tilting bodies whose perpendicular extent changes by being inclined. In order to increase the distance between the actuating elements, the vertical extent of the coupling elements has to increase when they are tilted.
According to a preferred embodiment of the invention, the movement elements can be coupled displaceably and/or pivotably to one another. The type of coupling can be freely selected in accordance with the particular application. It is therefore possible to design the embodiment in such a manner that optimum adaptation to the given requirements is ensured. At the forefront in this case are design constraints which predetermine the type of embodiment.
According to a further refinement of the invention, the fastening unit and the mechanical switching unit can be arranged together in a housing. The elements arranged therein are thus protected against external influences. Such an arrangement of the fastening unit and mechanical switching unit permits a compact construction which is secured during the painting cycle and at the same time avoids necessary maintenance work, since environmental influences, such as dirt, dust, moisture etc., are also prevented from acting on the elements present in the device.
According to a development of the invention, the housing can be an integral part of a movement element or can be arranged thereon. The use of part of a movement element as the housing reduces the necessary space required. In addition, this refinement achieves a saving on weight on the entire system. Should, for design reasons, it not be possible to use an integral part of a movement element as the housing, there is alternatively the option of securing a separate housing on a movement element in a space-saving manner.
According to the invention, the force can be generated by a force-application element. The action of a force on the braking elements is necessary in order to ensure the required blocking of the two movement elements. In addition to the use of a force-application element which applies the force necessary for this, it is also, for example, possible to use the existing weight of a movement element. If a separate force-application element is used, it is possible to precisely meter the necessary force in order to obtain optimum functioning of the fastener.
According to a development of the invention, the force-application element can be a spring. In this case, helical springs or cup springs, in particular, can be used in a space-saving manner. The dimensioning of the spring allows adaptation to the required conditions.
According to the invention, the switching unit can have a first and second actuating element, the first actuating element being connected to the first movement element and the second actuating element being connected to the second movement element in such a manner that the actuating elements change their relative position with respect to one another when the movement elements move with respect to one another.
A corresponding connection of the actuating elements to the respective movement elements makes it possible to achieve a change in position of the actuating elements by means of a customary operation of the movement elementsxe2x80x94for example, of a door with respect to a frame. The actuating elements form part of the switching unit and are connected directly to the movement elements. In a preferred embodiment, the actuating elements are formed by an upper and lower lifting washer. A mutual change in the position of the movement elements therefore causes a change in position of the actuating elements. In this arrangement, the movement elements can be connected to the actuating elements directly or via an intermediate gear mechanism. The use of a gear mechanism can contribute to facilitating the ease of operation if, for example, high forces occur in the system.
According to the invention, in the switching unit the actuating elements can change their distance apart and thereby can bring about a switching movement between the coupling state and the separating state. This change in distance enables the locking of the two movement elements to one another to be released because it leads to the power flow to the braking elements being interrupted.
According to a preferred embodiment of the invention, the first actuating element is arranged in a positionally fixed manner on the first movement element. A reduction in the number of movable parts reduces the risk of faults which may occur during the operation. Furthermore, a direct connection between the actuating element and movement element ensures a is problem-free transmission of force between the two elements.
According to a further refinement of the invention, the distance between the actuating elements can increase if they move with respect to one another from a first position, so that the second actuating element is, for example, raised if the two actuating elements are arranged one above the other. The arrangement of the actuating elements in the direction of the switching movements reduces the necessary overall size of the entire system.
According to a further refinement of the invention, the direction of the movement of the actuating elements, which movement is triggered by the movement of the movement elements, can be perpendicular to the direction of the switching movement. However, it is possible to change the orientation of the switching movement in accordance with the desired applications. An optimum refinement, in accordance with the particular application, of the invention is thus possible, the refinement being orientated to the given conditions, in particular space conditions.
According to the invention, the movement of the movement elements can cause a rotational movement of the actuating elements with respect to one another, the switching movement taking place in a direction which is parallel to the axis of rotation. If movement elements coupled pivotably to one another are used, the movement of the actuating elements therefore corresponds to the movements of the movement elements. It is therefore possible to dispense with possibly necessary changes in the direction of movement by means of complex gear mechanism constructions, which means a saving on weight, costs and space, amongst other things.
The advantageous refinements of the invention which are described in claims 9 and also 16 to 18 relate, among other things, to the type and arrangement of coupling elements and depressions on the actuating elements. The depressions serve in this case primarily to limit the inclination of the coupling elements and to position the coupling elements.
As an alternative to the use of separate switching elements, the actuating elements, which are designed as rings, can be of a corresponding design in their contact surface. In this case, it is, in particular, possible to provide the first actuating element in one piece as a profile with a projection, the projection interacting with a depression in the second actuating element.
By means of a corresponding shape of the depressions, it is also possible for rolling bodies which have a constant diameter to be used as coupling elements. The use of balls, for example, is thus possible if curved depressions are selected. When there is a relative movement of the actuating elements, the balls rise in the depressions and therefore increase the distance between the actuating elements.
The number of coupling elements and the associated depressions is orientated to the forces occurring during the switching. The force necessary for the switching is determined by the selection of the coupling elements and also by their arrangement on the actuating elements. It is thus possible to adjust the switching unit as desired in accordance with the stipulations via the coupling elements, among other things.
The advantageous refinements of the invention which are described in claims 10 to 15 relate, among other things, to the connection between the second actuating element and the second movement element. The refinements make provision for the second actuating element to be connected to the second movement element in a frictionally engaged manner. A thrust washer, which is arranged in a twist-proof and axially displaceable manner in the housing connected to the second movement element, can serve as the connecting element between the movement element and actuating element. In this embodiment of the invention, pivoting movements of the second movement element are transmitted directly to the thrust washer. The thrust washer, on the side which faces away from the actuating element, is subjected to pressure by the force which is applied, for example by a cup spring, which results in the formation of a frictionally engaged connection at a certain contact-pressure force between the second actuating element and the second movement element. That side of the second actuating element which is in contact with the thrust washer can have a sliding layer.
With an increasing change in distance between the actuating elements, the necessary force, which is necessary for a further change in distance, increases. In the process, in accordance with the selected pairing of material with the specified sliding layer, the stiction changes into the sliding friction state. The transition takes place after the switching movement is executed. In the sliding friction state, the force necessary for the relative change in position of the movement elements is reduced. It is possible, via the sliding layer, in conjunction with the position and type of coupling elements, to determine all of the forces necessary for the actuation.
According to a development of the invention, the first braking element can be connected in a twist-proof manner to the first movement element and the second braking element can be connected in a twist-proof manner to the second movement element. This embodiment of the invention relates, in particular, to movement elements which are connected in a rotationally hinged manner. In order to avoid a relative movement of the movement elements via the braking elements, it must be ensured that the braking elements do not move with respect to the movement elements. The fastening of the braking elements has to lead to the associated movement element being fastened. The braking elements should not be fixed perpendicularly to the direction of rotation, since the braking elements have to be moved relative to one another in order to be fastened or released and in order to execute a relative movement of the movement elements.
The advantageous refinements of the invention which are described in claims 20 to 23 relate, among other things, to the manner in which a thrust ring functions and to its interaction with brake discs which are used as the braking elements or as parts of said elements. The thrust ring is arranged in such a manner that in the coupling state it transmits the force from the thrust washer to the braking elements, so that the movement elements are fastened to one another. The thrust ring is understood to mean a component which, depending on the state of the switching unit, transmits the force from the thrust washer to the braking elements or separates them from the action of the force. In the event of the force transmission via the thrust washer, the braking elements, preferably brake discs, are pressed against one another, so that a frictional connection between the braking elements occurs.
In the separating state the second actuating element is displaced upwards, so that the frictional connection between the thrust washer and the thrust ring is interrupted and as a result the force is also prevented from acting on the discs.
The use of a thrust ring in conjunction with the thrust washer and also the use of the brake discs makes it possible to switch from the coupling state into the separating state in a minimal space.
When brake discs are used, there is the possibility of using one or more brake discs, depending on the application. It is additionally possible, by way of the selection of a suitable mating of material, to reduce the number of brake discs while retaining the desired locking force. In addition to the brake discs or else conical rings or cones which form a frictional connection, use can also be made of other braking elements, for example finely toothed braking elements, which form an interlocking connection.
The advantageous refinements of the invention which are described in claims 24 to 26 relate, inter alia, to the conversion of the described fastener to a frame-door system. When the first movement element is selected as a frame and the second movement element as a door which is pivotably coupled to the frame, the frame can be connected pivotably to the door via a hinge bolt, the hinge bolt extending in the housing. In such a refinement of the invention, the braking elements are in each case connected in a rotationally fixed manner to the hinge bolt or to the housing which is fixedly connected to the door. A spring arranged in the housing, for example, exerts pressure on the thrust washer, which is likewise secured in a rotationally fixed manner in the housing. During a pivoting movement, this thrust washer, in addition to the axial force component, transmits a rotational force to the associated actuating element which is in engagement with the actuating element of the hinge bolt via the coupling element.
A thrust ring arranged radially around the switching unit can transmit the axial force to the brake discs when the system is at a standstill, as a result of which said brake discs are brought into mutual engagement.
When applied to a preferred use and design of the invention, the following sequence is produced: at the beginning of a rotational movement of the door the distance between the actuating elements increases, as a result of which the spring-loaded thrust washer is displaced axially and the frictional connection between the thrust washer and thrust ring is interrupted. Since the counterforce, which holds the switching unit out towards the actuating force, increases as the relative movement of the actuating elements increases, at a defined position the thrust washer, as a consequence of the sliding layer, begins to slide, thereby enabling the door to pivot freely. Once the door is released, the distance between the actuating elements is reduced again, as a result of which the braking elements enter into engagement again and the door is fastened. The reduction in the distance between the actuating elements is associated with the door briefly pivoting back counter to the preceding direction of movement. This makes it possible to open the door virtually completely as far as an obstacle which may be present. Once the door is released, a margin of safety between the door and the obstacle is formed automatically by the restoring force of the door or manually by the door briefly pivoting back.
According to a preferred embodiment of the invention, a braking device, which is formed by the braking elements, is mounted directly on a hinge with which the movement elements are coupled pivotably to one another. This embodiment of the invention makes it possible, inter alia, for production costs to be reduced, since the fastener is not installed additionally to the existing hinges, but rather is integrated in one of the existing hinges.
According to a development of the invention, the housing can be configured in such a manner that in the closed state of the door the switching unit is fixed in the uncoupled state. As described previously, in the case of a door the switching unit switches in both directions of movement, i.e. both in the closing direction and in the opening direction. This would mean that the switching unit is fixed in the uncoupled state when the door is closed. However, this would have the consequence that when the door is opened, switching has to take place from the uncoupled state via the coupling state back into the uncoupled state. The development of the invention which is shown can prevent, when the door is opened, switching into the coupling state from taking place in the meantime. Via the angular range of which the bolt is in engagement with the second actuating element, the angular range can be determined in which the switching unit is blokked and therefore does not switch into the coupling state.